Video router

ABSTRACT

The embodiments described herein provide a data transmission system comprising a plurality of video routers, a supervisory system for transmitting one or more router configuration signals to one or more video routers, and a control communication network for coupling the plurality of video routers and the supervisory system. Each router in the system comprises a backplane including a plurality of backplane connections, at least one line card and at least one fabric card. Each line card comprises a plurality of input ports and output ports where each input and output port is coupled to a respective external signal through the backplane. Each line card further comprises a line card cross-point switch having a plurality of input switch terminals and a plurality of output switch terminals. Each fabric card comprises a fabric card cross-point switch having a plurality of input switch terminal and a plurality of output switch terminals. Furthermore, each line card and each fabric card comprises a card controller where the card controller selectively couples one or more input switch terminals of a cross-point switch to the output switch terminals of that cross-point switch. The cross-point switches being manipulated by the card controller may belong to one or more different cards within the same video router.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/190,659, filed on Nov. 14, 2018, which is a continuation of U.S.patent application Ser. No. 15/910,099, filed on Mar. 2, 2018 (nowissued as U.S. Pat. No. 10,164,877), which is a continuation of U.S.Patent Application No. 15/484,852, filed on April 11, 2017 (now issuedas U.S. Pat. No. 9,942,139), which is a continuation of U.S. patentapplication Ser. No. 14/505,124, filed on Oct. 2, 2014, (now issued asU.S. Pat. No. 9,654,391), which claims the benefit of U.S. ProvisionalPatent Application No. 61/885,588, filed Oct. 2, 2013. The entirecontents of the applications are hereby incorporated by reference.

FIELD

The described embodiments relate to routers for video signals and otherdata streams.

BACKGROUND

The number of devices coupled to data communications networks isincreasing rapidly. The routing of data streams from and to such devicesis increasingly more complex and difficulty in allocating efficientroutes, or even any route at all, in various components in acommunication network can affect the quality of service delivery to auser of a device. For example, communication networks typically containrouters that couple an input data stream received at an input port to anoutput port at which the data stream is available to a downstreamdevice. As the size of routers increases (i.e. as the number of inputand output ports on a router increases, then complexity of creatingefficient routing within the router and between network devices increasenon-linearly.

It is desirable to provide an efficient system and methods that allows anetwork device to efficiently configure routes for data streams.

SUMMARY

In one aspect, in at least one embodiment described herein, there isprovided a data transmission system comprising a plurality of videorouters, a supervisory system for transmitting one or more routerconfiguration signals to one or more video routers, and a controlcommunication network for coupling the plurality of video routers andthe supervisory system. Each router in the system comprises a backplaneincluding a plurality of backplane connections, at least one line cardand at least one fabric card. Each line card comprises a plurality ofinput ports and output ports where each input and output port is coupledto a respective external signal through the backplane. Each line cardfurther comprises a line card cross-point switch having a plurality ofinput switch terminals and a plurality of output switch terminals. Eachfabric card comprises a fabric card cross-point switch having aplurality of input switch terminal and a plurality of output switchterminals. Furthermore, each line card and each fabric card comprises acard controller where the card controller selectively couples one ormore input switch terminals of a cross-point switch to the output switchterminals of that cross-point switch. The cross-point switches beingmanipulated by the card controller may belong to one or more differentcards within the same video router.

In some cases, the card controller of a first card in a first videorouter configures a corresponding cross-point switch of the first cardto route a data stream from an input port to an output port, where thefirst card and the second card are a line card or a fabric card.

In some other cases, the card controller of a first card in a firstvideo router configures a cross-point switch of a second card in thefirst video router to route a data stream from an input port to anoutput port, where the first card and the second card are a line card ora fabric card.

In various cases, where when a data stream is received at an input portof a first card, a first card controller corresponding to the first cardis configured to transmit a data request to the supervisory system,where the supervisory system is configured to: determine an outputdestination identifying an output port, and generate one or more routerconfiguration signals for one or more card controllers based on theoutput destination, wherein the one or more card controllers configureone or more cross-point switches to route the data stream to the outputport.

In various cases, where when a data stream is received at an input portof a first card, a first card controller corresponding to the first cardis configured to: determine an output destination identifying an outputport, and transmit a data request to the supervisory system, where thesupervisory system is configured to: generate one or more routerconfiguration signals for one or more card controllers based on theoutput destination, wherein the one or more card controllers configureone or more cross-point switches to route the data stream to the outputport.

In various cases, where if the data stream is designated a prioritystream, at least one of the one or more card controllers reconfiguresthe corresponding cross-point switch to route the priority stream.

In various cases, where the backplane comprises a plurality of backplaneconnectors for receiving the at least one line card and the at least onefabric card.

In various cases, where each backplane connector comprises a pluralityof backplane contacts, wherein each line card and each fabric cardcomprises a plurality of card pins, and wherein the plurality ofbackplane contacts and the plurality of card pins provide an electricalconnection when coupled.

In various cases, the system further comprises a switch configurationdatabase coupled to the controller communication network and configuredto store coupling of the input switch terminals of at least one linecard cross-point switch and the fabric card cross-point switch tocorresponding output switch terminals.

In various cases, the switch configuration database is provided withinthe card controllers.

In another aspect, in at least one embodiment described herein, there isprovided a method of routing video signals from a plurality of inputports to a plurality of output ports using at least one video router ofa data transmission system disclosed herein. The method comprisesreceiving a data stream at an input port of a card, the card being aline card, receiving one or more router configuration signals by one ormore card controllers, at least one card controller being a line cardcontroller of the line card, and configuring one or more cross-pointswitches by card controllers based on the one or more routerconfiguration signals to route the data stream between the input portand an output destination, wherein at least one of the one or morecross-point switches correspond to a cross-point switch of the linecard.

In various embodiments, the method of routing video signals isconfigured to operate in accordance with the devices defined above or inaccordance with the teachings herein.

In another aspect, in at least one embodiment described herein, there isprovided a data transmission system comprising a control layer, a datalayer and a controller communication network for coupling the controllayer and the data layer. The control layer comprises a supervisorysystem configured to transmit one or more router configuration signalsto one or more video routers, the one or more router configurationsignals comprising instructions to selectively configure the one or morerouters, and one or more card controllers provided in the one or morevideo routers, each card controller configured to selectively coupleinput switch terminals of one or more cross-point switches to outputswitch terminals of the corresponding one or more cross-point switches.The data layer comprises one or more cross-point switches, the one ormore cross-point switches provided in the one or more video routers,each cross-point switch comprising a plurality of input switch terminalsand a plurality of output switch terminals, a backplane including aplurality of backplane connections, wherein a subset of the plurality ofinput switch terminals and the output switch terminals are coupled to arespective plurality of backplane connections, a plurality of inputports and a plurality of output ports corresponding to each videorouter, where the supervisory system is configured to: receive a requestsignal from a card controller, and transmit a router configurationsignal to one or more card controllers, the router configuration signalcomprising instructions to selectively couple input switch terminals tooutput switch terminals of the one or more cross-point switches coupledto the one or more card controllers.

In various embodiments, the data transmission system is configured tooperate in accordance with the devices and methods defined above or inaccordance with the teachings herein.

Other features and advantages of the present application will becomeapparent from the following detailed description taken together with theaccompanying drawings. It should be understood, however, that thedetailed description and the specific examples, while indicatingpreferred embodiments of the application, are given by way ofillustration only, since various changes and modifications within thespirit and scope of the application will become apparent to thoseskilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the applicant's teachings describedherein, reference will now be made, by way of example only, to theaccompanying drawings which show at least one exemplary embodiment, andin which:

FIG. 1 is a cross-section of a video router according to an exampleembodiment;

FIG. 2 is a cross-section of a video router according to another exampleembodiment;

FIG. 3 is a block diagram of a video router according to an exampleembodiment;

FIG. 4 is a block diagram of a video router according to another exampleembodiment;

FIG. 5 is a block diagram of a video router according to another exampleembodiment;

FIG. 6 is a block diagram of a video router according to another exampleembodiment;

FIG. 7 is a block diagram of a control hierarchy of a video routeraccording to an example embodiment.

For simplicity and clarity of illustration, elements shown in thefigures have not necessarily been drawn to scale. For example, thedimensions of some of the elements may be exaggerated relative to otherelements for clarity. Further, where considered appropriate, referencenumerals may be repeated among the figures to indicate corresponding oranalogous elements.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference is first made to FIGS. 1 and 2, which illustrates a firstvideo router 100 with an integrated control layer. Router 100 includes aframe or housing 102, a backplane 104 and a plurality of cards 106, suchas a first card 106 a, a second card 106 b, a third card 106 c, a fourthcard 106 d, a fifth card 106 e and a sixth card 106f. The frame 102includes a plurality of frame slots 108 in which cards may be receivedand held in place. The backplane 104 includes backplane connector 110corresponding to each slot 108 and each card 106. Each backplaneconnector includes a plurality of backplane pins or contacts 112. Eachcard 106 includes a plurality of card pins or contacts 114, each ofwhich corresponds to a backplane pin 112 of the corresponding backplaneconnector. When a card 106 is installed in frame 102, the card pins 114couple with corresponding backplane pins 112 making an electricalconnection through which a data signal may be transmitted.

Cards 106 may include various types of cards. For example, some of thecards may be line cards 116, such as a first line card 116 a and asecond line card 116 d, which include input ports or output ports forrespectively receiving and transmitting data signals, or both input andoutput ports. Other cards 106 may be fabric cards 140, such as a firstfabric card 140 b and a second fabric card 140 c, which facilitateswitching of signals between various input and port ports.

Reference is made to FIGS. 3, 4 and 5, which schematically illustratecomponents of router 100. In the present example embodiment, each inputport 118 or output port 120 on a line card 116 a is coupled to anexternal signal through the backplane 104. In the illustrated embodimentof FIG. 3, input port 118 comprises a first input port 118 a, a secondinput port 118 b and a third input port 118 c, and output port 120comprises a first output port 120 a, a second output port 120 b, a thirdoutput port 120 c and a fourth output port 120 d. The backplane may, forexample, include a pass-through connector to which a line card port 118,120 may be coupled within frame 102 and to which a cable (not shown) maybe coupled on the rear of the backplane. The line card port 118, 120 iselectrically coupled to the cable (not shown), allowing the line card toreceive or transmit a data signal on the cable. In other embodiments,line card ports may be directly coupled to a cable or may be coupled toa cable through the backplane using a coupling other than a pass-throughconnector.

Line card 116 a includes a line card crosspoint switch 124 a with aplurality of switch terminals. In this example, crosspoint switch 124 ahas a plurality of input switch terminals 128 and a plurality of outputswitch terminals 130. Each input port 118 is coupled to at least oneinput switch terminal 128 and each output port 120 is coupled to atleast one output switch terminal 130. In addition, a plurality of inputswitch terminals 128 are coupled to the backplane 104 through thecorresponding backplane connector 110. A plurality of output switchterminals 130 are coupled to the backplane 104 through the correspondingbackplane connector 110.

Line card 116 a also includes a line card controller 132 a that iscoupled to crosspoint switch 124 a and which provides control signals tocouple or decouple particular input switch terminals 128 to particularoutput switch terminals 130. Card controller 132 a is coupled to acontroller communication network 136 at a control system terminal 134 athrough which the card controller 132 a may communicate with other cards106 and with external control devices such as an external supervisor138. In some embodiments, a line card controller 132 a may be coupled tocontroller communication network 136 through the backplane or throughanother communication bus in frame 102 to which the line card is couplewhen installed in the frame.

Each fabric card, such as fabric card 140 b includes a card controller132 b and a crosspoint switch 124 b, which are coupled together andoperate in a manner similar to the card controller 132 a and crosspointswitch 124 a of line card 116 a. Crosspoint switch 124 b includes aplurality of input switch terminals 128 and output switch terminals 130that are coupled to the backplane 104. The crosspoint switch 124 b maybe configured to couple any of the input switch terminals 128 to any ofthe output switch terminals 130 under the control of card controller 132b. As illustrated in FIG. 3, router 100 further includes a fabric card140 c, which includes a card controller 132 c and a crosspoint switch124 c, and a line card 116 d, which includes a card controller 132 d anda crosspoint switch 124 d.

Each crosspoint switch 124 a, 124 b, 124 c, 124 d in router 100 iscoupled to the controller communication network 136 through which theconfiguration of the crosspoint switch 124 a, 124 b, 124 c, 124 d may bechanged by card controller 132 a, 132 b, 132 c, 132 d on other cards106.

Router 100 also includes a switch configuration table or database 150.Database 150 records the current setting for every input switch terminaland output switch terminal in all cross-point switches 124 a, 124 b, 124c, 124 d in the router 100. For example, part of the contents ofdatabase 150 may be:

Switch Terminal Setting 124a 128a1 Coupled to 130c3 124a 128a2 Coupledto 130a27 124a 128a3 Open 124a 128a4 Coupled to 130a8 . . . . . . . . .124a 130a3 Coupled to 128a1 124a 130a4 Open 124a 130a5 Coupled to 128a2124a 130a6 Open 124a 130a7 Coupled to 128a2 124b 130a8 Coupled to 128a4. . . . . . . . . 124b 128b1 Open . . . . . . . . . 124c 128c35 Coupledto 130c14 . . . . . . . . . 124c 130c14 Coupled to 128c35 . . . . . . .. . 124d 128d12 Coupled to 130d5 124d 130d5 Coupled to 128d12 . . . . .. . . .where router 100 of FIG. 4 comprises a first input port 118 a 1, asecond input port 118 a 2, a third input port 118 a 3, a fourth inputport 118 a 4, a fifth input port 118 a 5, a sixth input port 118 a 6, aseventh input port 118 a 7, a first output port 120 a 1, a second outputport 120 a 2, a third output port 120 a 3, a fourth output port 120 a 4,a fifth output port 120 a 5, a sixth output port 120 a 6, a seventhoutput port 120 a 7, a first input switch terminal 128 a 1, a secondinput switch terminal 128 a 2, a third input switch terminal 128 a 3, afourth input switch terminal 128 a 4, a fifth input switch terminal 128a 5, a sixth input switch terminal 128 a 6, a seventh input switchterminal 128 a 7, an nth input switch terminal 128 an, a (n+1)th inputswitch terminal 128 a (n+1), a (n+2)th input switch terminal 128 a(n+2), a first output switch terminal 130 a 1, a second output switchterminal 130 a 2, a third output switch terminal 130 a 3, a fourthoutput switch terminal 130 a 4, a fifth output switch terminal 130 a 5,a sixth output switch terminal 130 a 6, a seventh output switch terminal130 a 7, an nth output switch terminal 130 an, a (n+1)th output switchterminal 130 a(n+1) and a (n+2)th output switch terminal 130 a(n+2).

Database 150 is accessible to each of the controllers 132 a, 132 b, 132c, 132 d. In some embodiments, the database 150 may be recorded in acentral location, for example, in one of the controllers 132 a, 132 b,132 c, 132 d where the local controller 132 a, 132 b, 132 c, 132 d mayaccess the database directly and each of the other controllers mayaccess the database through the controller communication network 136.

In other embodiments, the database may be a distributed database withcomponents that are located in multiple locations within router 100. Forexample, components of database 150 a, 150 b may be located in each ofthe controllers 132 a, 132 b, as is illustrated in FIGS. 4 and 5. Eachcontroller 132 a, 132 b may contain the status of the cross-point switch124 a, 124 b in the same card 106. Controllers 132 a, 132 b, 132 c, 132d on other cards 106 may access the status of non-local cross-pointsswitches through the controller communication network 136.

In other embodiments, the database may be recorded in a data storagedevice or system that is external to router 100, but which is accessibleto the controller 132 a, 132 b, 132 c, 132 d.

In still other embodiments, a copy of the entire database 150 may bemaintained at each controller 132 a, 132 b, 132 c, 132 d. Asynchronization system that locks some or all of each copy of thedatabase may be used to ensure that all copies of the database 150 aremaintained in synchronization. In such embodiments, each controller 132a, 132 b, 132 c, 132 d may use only its local copy of the entiredatabase 150.

In various embodiments, a combination of these techniques may be used tomaintain database 150.

As illustrated in FIG. 5, the backplane 104 includes a plurality ofstatic point-to-point backplane connections 152 that couple outputswitch terminals on one card 106 to input switch terminals on anothercard 106. For example, backplane connections may couple output switchterminal 130 a 27 on line card 116 a to input switch terminal 128 c 35on fabric card 140 c. Various embodiments may include as many or as fewbackplane connections between output switch terminals to input switchterminals.

In any particular embodiment, the sizes of the various crosspointswitches 124 a, 124 b, 124 c, 124 d and the number of backplaneconnections can be selected to provide a desired level of functionalityin the router. For example, in a router designed for a specific purpose,for example, in which only a limited number of couplings between inputports 118 and output ports 120 may be required, may have acorrespondingly limited number of backplane connections 152. Fabriccards are typically useful to increase the flexibility with which aparticular input port can be coupled to a particular output port. Insome embodiments, all cards 106 may be line cards with no fabric cards.

By selectively configuring one or more crosspoint switches 124 a, 124 b,124 c, 124 d, a particular input port 118 on one line card 116 may becoupled to a particular output port 120 on the same or another linecard.

Reference is made to FIG. 4. For example, if:

input port 118 a 4 is fixedly coupled to input switch terminal 128 a 4;

switch crosspoint switch 124 a couples input switch terminal 128 a 4 tooutput switch terminal 130 a 7; and

output switch terminal 130 a 7 is fixedly coupled to output port 120 a7, then an input data signal received input port 118 a 4 on line card116 a will be coupled to output port 120 a 7.

Reference is made to FIG. 6. If:

input port 118 a 2 is fixedly coupled to switch input terminal 128 a 2;

switch input terminal 128 a 2 is coupled to output switch terminal 130 a27 in crosspoint switch 124 a;

output switch terminal 130 a 27 is coupled to input switch terminal 128c 35 in fabric card 140 c through backplane connection 152 a;

switch input terminal 128 c 35 is coupled to output switch terminal 130c 14 in crosspoint switch 124 c;

output switch terminal 130 c 14 is coupled to input switch terminal 128d 12 through the backplane connection 152 b;

switch input terminal 128 d 12 is coupled to output switch terminal 130d 5 in crosspoint switch 124 d; and

output switch terminal 130 d 5 is fixedly coupled to output port 120 d5, then an input data signal received at input port 118 a 2 on line card116 a will be coupled to output port 120 d 5 on line card 116 d.

In router 100, each controller 132 a, 132 b, 132 c, 132 d is coupled toeach crosspoint switch 124 a, 124 b, 124 c, 124 d in the router and mayinstruct any crosspoint switch 124 a, 124 b, 124 c, 124 d to couplespecific input switch terminals and output switch terminals within thecrosspoint switch 124 a, 124 b, 124 c, 124 d. Through one or more stepsthrough crosspoint switches and through backplane connection 152, aninput signal received at an input port 118 may be coupled to an outputport 120 on the same or a different line card. In some embodiments, thecrosspoint switches and the number of pairs of output switch terminalsand input switch terminals coupled by backplane connections 152 may besufficient to allow any input port 118 to be coupled to any output port120, possibly through a variety of different routes.

A particular controller 132 a, 132 d in a line card 116 a, 116 d may beconfigured to ensure that a data signal or data stream received at theline card is routed through to an appropriate destination for the datastream. For example, when a data stream is initially received at aninput port 118, the controller examines the packets in the data stream,which will identify a destination for the data stream. The controllerthen determines which output port 120 in the router (which may be on thesame line card as the controller or on another line card) is coupled tothe destination. The controller then determines a path through therouter and configures one or more crosspoint switches to provide thepath between the input port 118 and the output port 120. The controllerwill typically select a route based on router configuration data that ispreviously recorded in the controller. The router configuration dataincludes information about the availability of backplane connectionsbetween different cards and may include additional information about therouter structure or configuration. The controller will also typicallyconsider the contents of the database 150. Typically a controller willnot change the configuration of an input switch terminal or an outputswitch terminal that is already in use (i.e. coupled to a correspondingswitch terminal). In some embodiments, a priority level for some or allof the couplings between different pairs of input switch terminal andoutput switch terminal may be maintained in database 150. A controllermay determine a priority level for a data stream that the controller isrouting through router 100. If an input switch or an output switchterminal is in use, but the stored priority level for the stream beingrouted through the switch is lower than the priority of the stream thatthe controller is attempting to route, then the control may change theconfiguration of the switch to use it for the higher priority datastream. In some cases, the router may have multiple paths through whicha data stream can be routed from a particular input port 118 to aparticular output port 120 and it may be possible to provide a neededrouting for a high priority data stream without disrupting a lowerpriority data stream. Each controller may be configured to identifymultiple routings to reduce disruption to existing routes set up withinthe router.

In some conditions, a controller may not be able to determine a route bywhich a data stream can be delivered to a particular output port 120. Insuch conditions, the controller 132 may send a routing request to asupervisor 138 through the controller communication network 136. Asupervisor will typically be an external device that can monitor andcontrol the configuration of crosspoint switches 124 a, 124 b, 124 c,124 d in the router 100 and possibly in other routers. In someembodiments, a supervisor 138 may be built into a router. In someembodiments, duplicate or multiple supervisors may be provided toprovide redundancy or improved responsiveness when a request is sent toa supervisor or a group of supervisors.

Each time a controller 132 a, 132 b, 132 c, 132 d changes theconfiguration of a switch 124 a, 124 b, 124 c, 124 d, the changes arerecorded in the database 150.

A supervisor may receive various types of requests. For example, acontroller may ask a supervisor to provide a route from a particularinput port to a particular output port. A controller may ask asupervisor to examine a packet to determine the output port to which thepacket (and the corresponding data stream) should be coupled, andpossibly also to provide a routing between the input port on which thedata stream is received and the output port.

In some embodiments, a supervisor may directly change the configurationof crosspoint switches 124 a, 124 b, 124 c, 124 d and update database150 and advise the requesting controller that the request has beensatisfied and optionally provide details of configuration changes madein the router. In other embodiments, a supervisor may provide a responseto a controller making a request and the controller may then implementthe details of the response.

In some embodiments, each controller 132 a, 132 b, 132 c, 132 d mayrecord some or all of the routes that are used by the controller,including some or all of the requests provided by a supervisor. Thecontroller 132 a, 132 b, 132 c, 132 d may subsequently refer to therecorded requests to select routes for data streams between input ports118 and output ports 120 based on the previously recorded routes. Insome embodiments, the controller may track performance information suchas the frequency with which transmission failures occur in particularroutes and may select more reliable routes. Over time, the recordedroute may become a library allowing a controller 132 a, 132 b, 132 c,132 d to resolve an increasing number of routing requirement withoutsending a request to a supervisor. In addition, some or all of thecontrollers may be configured to find routes without reference topreviously recorded route or making a request to a supervisor.

In this manner, the controllers 132 a, 132 b, 132 c, 132 d in each card106 are able to provide routes for data streams through the router 100.Some of the routes may traverse only the line card on which a datastream is received while other routes may traverse various line cards,fabric cards and backplane connections. In doing so, the controller canreduce the number of requests transmitted to the supervisor, increasingthe rate at which data streams can be coupled through a router,particularly when a router receives, routes and transmits a large numberof data streams.

Router 100 has been described as a video router. A video router willtypically receive audio/video data streams (which may be referred to astransport streams). In some embodiments, the data streams may alsoinclude non-video streams or may not include any video streams at all.

Reference is next made to FIG. 7, which illustrates a control hierarchybetween the card controllers, supervisors, other routers and otherdevices in a system. In some situations, a plurality of routers 700 maybe coupled to provide a data transmission system. For example, routers700 may be installed in a video processing facility such as a televisionstudio or broadcast facility. Some or all of the routers may receive andtransmit a plurality of input and output data streams. In somefacilities, hundreds, thousands or even millions of data streams may bereceived and transmitted. The group of routers will typically beinterconnected with a variety of other equipment including signalprocessors, analytic devices and other devices that generate or requiredata streams that are switched through one or more routers.

Each router 700 is coupled to a supervisor system 754, which may includea plurality of supervisors 738, such as a first supervisor sub-system738 a, a second supervisor sub-system 738 b, a third supervisorsub-system 738 c, a fourth supervisor sub-system 738 d, a fifthsupervisor sub-system 738 e, a sixth supervisor sub-system 738 f, aseventh supervisor sub-system 738 g and an eighth supervisor sub-system738 h. The supervisor system 754 forms a hierarchy in conjunction withthe controllers 732 in each router. As described above, a cardcontroller 732 on a card 706, including a line card 716 and a fabriccard 740, in a router 700 may control the configuration of thecorresponding switch 724 on its card 706 and may also be authorized tocontrol the configuration of switches 724 on other cards within the samerouter. The controller may send requests to a corresponding supervisorsub-system 738 a when the controller is unable to determine a route fora data stream, for example, when the controller is unable to allocateswitches or connections to set up a required route, or when a route mayrequire coordination between routers or under other conditions, whichmay include instructions from a supervisor to always make a request tothe supervisor when certain types of data streams are received or aftera particular time or other conditions. In some cases, two or moresupervisors may be assigned to each router and may act as primary andbackup routers, may operate in parallel, or may operate in a distributedmanner to manage the flow and latency or requests made to thesupervisory system 754.

The supervisory system 754 may itself be coupled to other devices in afacility via a controller communication network 736 to receive andprovide control and status information about the routers 700. Suchcontrol and status information may be used to control the routing ofdata streams within and between routers 700. For example, the otherdevices in the facility may identify high priority data streams that areto be switched through one or more routers 700 to reach a particulardestination. Supervisor system 754 may instruct one or more of therouters to configure an appropriate route between a port on which a highpriority data stream is to be received and its destination. In such asituation, a supervisor sub-system 738 may instruct the routers toconfigure a route directly, without previously having received a requestfrom a controller 732.

FIG. 7 illustrates a control hierarchy in which the supervisory system754 communicates with other devices, which may be at the same or adifferent facility as the supervisory system. Supervisors 738 in thesupervisor system 754 control the routing of data streams within andbetween the routers and between the routers and other devices.Controllers 732 in the routers can control routes directly within therouter and may request control instructions from supervisors to generaterequests. The supervisory system 754 and the controllers 732 are part ofa control layer 756 that provides routes for data streams.

FIG. 7 also illustrates a data layer 758 in which the data streams aretransmitted. The data layer 758 includes input ports 718, switches 724,backplane connections 752 and output ports 720. The control layer 756configures the data layer so that data streams are able to traverse thedata layer between input ports and output ports.

The present invention has been described here by way of example only.Various modification and variations may be made to these exemplaryembodiments without departing from the scope of the invention, which islimited only by the appended claims.

1.-20. (canceled)
 21. A video router comprising: a backplane including aplurality of backplane connections; at least one line card, each linecard comprising: a plurality of input ports and output ports, each inputport and output port is coupled to a respective data signal through thebackplane. a line card cross-point switch having a plurality of inputswitch terminals and a plurality of output switch terminals, wherein afirst plurality of input and output switch terminals are coupled to arespective plurality of input and output ports and a second plurality ofinput and output switch terminals are coupled to the plurality ofbackplane connections; a line card controller coupled to the line cardcross-point switch to selectively couple some of the input switchterminals to the output switch terminals; at least one fabric card, eachfabric card comprising: a fabric card cross-point switch having aplurality of input switch terminals and a plurality of output switchterminals coupled to the plurality of backplane connections; a fabriccard controller coupled to the fabric card cross-point switch toselectively couple some of the input switch terminals to the outputswitch terminals; and a controller communication network coupled to eachof the line cards and fabric cards to control the operation of thefabric card controllers and the line card controllers.
 22. The videorouter of claim 21, further comprising a switch configuration databasecoupled to the controller communication network and configured to storecoupling of at least one of the input switch terminals of the line cardcross-point switch and the fabric card cross-point switch to acorresponding output switch terminal.
 23. The video router of claim 22,wherein the switch configuration database is stored in the fabric cardcontrollers and the line card controllers.
 24. The video router of claim22, wherein the switch configuration database is stored in an externaldata storage device and is accessible by the fabric card controllers andthe line card controllers.
 25. The video router of claim 22, wherein oneor more controllers configure one or more corresponding cross-pointswitches to route a data stream from an input port to an output port,wherein each of the one or more controllers being a fabric cardcontroller or a line card controller, and the corresponding cross-pointswitches being a corresponding fabric card cross-point switch or a linecard cross-point switch.
 26. The video router of claim 25, wherein whenthe data stream is received at the input port, a controllercorresponding to at least one of the one or more line cards and the oneor more fabric cards processes the data stream and generates an outputdestination identifying the output port for the data stream.
 27. Thevideo router of claim 25, wherein if the data stream is designated apriority stream, at least one of the one or more controllersreconfigures the corresponding cross-point switch to route the prioritystream.
 28. The video router of claim 21, wherein the backplanecomprises a plurality of backplane connectors for receiving the one ormore line cards and the one or more fabric cards.
 29. The video routerof claim 28, wherein each backplane connector comprises a plurality ofbackplane contacts, wherein each of the one or more line cards and theone or more fabric cards comprises a plurality of card pins, and whereinthe plurality of backplane contacts and the plurality of card pinsprovide an electrical connection when coupled.
 30. The video router ofclaim 28, wherein the backplane further comprises a plurality ofpoint-to-point traces, each point-to-point trace being configured tocouple an output switch terminal of a first card to an input switchterminal of a second card, each of the first card and the second cardbeing a line card or a fabric card.
 31. The video router of claim 30,wherein the plurality of point-to-point traces are static traces. 32.The video router of claim 25, wherein the data stream comprises dataselected from the group consisting of audio data, video data, and acombination of audio and video data.
 33. A method of routing videosignals from a plurality of input ports to a plurality of output portsusing the at least one video router of claim 21, the method comprising:receiving a data stream at an input port of a first card, the first cardbeing a line card; receiving at least one router configuration signal byat least one card controller, the router configuration signal comprisinginstructions to selectively couple input switch terminals to outputswitch terminals of one or more cross-point switches, wherein at leastone of the one or more cross-point switches correspond to a firstcross-point switch of the first card, and at least one of the at leastone card controller corresponds to a first line card controller of thefirst card; and configuring the one or more cross-point switches, bycorresponding card controllers, based on the router configuration signalto route the data stream between the input port and the outputdestination.
 34. The method of claim 33, further comprising: configuringat least one additional cross-point switch other than the firstcross-point switch, wherein the one additional cross-point switch isincluded in a second card coupled to the first card, the second cardbeing a fabric card or a line card.
 35. The method of claim 33, furthercomprising: transmitting a routing request to an external device; andreceiving the at least one router configuration signal from the externaldevice.
 36. The method of claim 33, wherein each controllercorresponding to the one or more cross-point switches comprises aconfiguration database configured to store coupling instructions betweeninput switch terminals to the output switch terminal of thecorresponding cross-point switch.
 37. The method of claim 33, whereineach controller corresponding to the one or more cross-point switches iscoupled to a configuration database using a controller communicationnetwork, wherein the configuration database is configured to storecoupling instructions between input switch terminals to the outputswitch terminal of the corresponding cross-point switch.
 38. The methodof claim 33, wherein if the data stream is designated a priority stream,the method comprises: determining if reconfiguration of the one or morecross-point switches is required to route the priority stream before asecond data stream, the second data stream having a lower priority thanthe priority stream; and if reconfiguration is required, reconfiguringthe one or more cross-point switches.
 39. The method of claim 33,further comprising: monitoring one or more performance characteristicsof the at least one video router to generate monitored performance data;and reconfiguring the one or more cross-point switches based on themonitored performance data.
 40. The method of claim 39, wherein at leastone performance characteristic comprises frequency of transmissionfailure of the data stream between an input port and an output port.